MAMMOTH LAKES, Calif. — Snowboarder Chelone Miller, the younger brother of Olympic gold medalist Bode Miller, died Sunday in the area of Mammoth Lakes, Calif. He was 29.

The Mono County Sheriff’s Office confirmed his death Monday in a statement. The cause of death is being investigated, but authorities say foul play is not suspected.

According to the statement, the sheriff’s office dispatch received a call around 12:45 p.m. Sunday regarding an unresponsive male in his van. Paramedics, the fire department and deputies were dispatched to the scene, whereupon arrival “it was determined that Mr. Miller was deceased,” the statement said.

Miller, of Easton, N.H., was hoping to make the U.S. squad in snowboardcross for the 2014 Sochi Games. Nicknamed Chilly, Miller recently finished fourth at the 2013 U.S. Snowboarding Grand Prix in Canyons, Utah.

In addition to competing, Miller also did some filming with Warren Miller and other production companies.

“Chelone Miller was an aspiring elite athlete who had made great progress as a snowboardcross rider this past season. We are all deeply saddened at the news of his death and extend our condolences to the entire Miller family,” U.S. Ski and Snowboard Association President Bill Marolt said in a statement on the team’s website.

Several Olympic athletes took to Twitter to express their condolences:

—Freestyle skier and two-time Olympian Emily Cook: “Broken-hearted to hear of the passing of Chelone Miller. Sending love and prayers to Bode, friends and family.”

—Snowboarder Elena Hight: “My heart goes out to (at)MillerBode and his family. So sad for the loss of such a great person. (hash)RIPchilly.”

Just last month, Chelone Miller won the Rahlves Banzai Tour overall title courtesy of a victory at Sugar Bowl in California. The event is organized by Daron Rahlves, a former World Cup and Olympic skier. The Twitter account (at)RahlvesBanzai tweeted: “RIP Chilly..We will miss you, but never forget! Thoughts go out to (at)MillerBode and his family.”

Bode Miller is a five-time Olympic medalist in alpine skiing. He sat out the 2012-13 World Cup season while recovering from a knee injury.